A God-commanded work of love. Plural: mitzvot.
The mi in front of the root tzavoh, command, makes it passive, a “good work” or “love offering,” but not commanded. However, metzaveh is active, a real command. God commanded us, “All the commandment [kol ha-mitzvah] which I command [anokhi metzaveh] you this day you shall be careful to do” Deut 8:1.
God’s people Israel had an integral understanding of the Law. An Israelite who transgressed any one mitzvah was guilty of transgressing them all.
The Catholic Church understands God’s law the same way. A single unrepented mortal sin can send us to hell for all eternity § 1857. Our first parents committed only one mortal sin Gen 3:6, and were driven out of paradise Gen 3:24. The Catechism of the Catholic Church, in its Glossary, states under Punishment, Eternal, “The penalty for unrepented mortal sin, separating the sinner from communion with God for all eternity; the condemnation of the unrepentant sinner to hell” p. 896.
Behold, the days are coming, says the Lord, when I will make a new covenant with the house of Israel and the house of Judah, not like the covenant which I made with their fathers when I took them by the hand to bring them out of the land of Egypt, my covenant which they broke, though I was their husband, says the Lord. But this is the covenant which I will make with the house of Israel after those days, says the Lord: I will put my law within them, and I will write it upon their hearts; and I will be their God, and they shall be my people Jer 31:31–33.